Slice the
beef into long narrow strips and thread, zig-zag, onto 12 bamboo
skewers. Lay on a flat plate and set aside. For the marinade, dry fry
the seeds and nuts in a large wok until evenly brown. Place in a pestle
and mortar with a rough surface and crush finely. Alternatively, blend
the spices and nuts in a food processor. Add the vegetable oil, shallots
or onion, ginger, garlic, tamarind and soy sauces, sugar and vinegar.
Spread this mixture over the beef and leave to marinate for up to 8
hours. Cook the beef under a moderate grill (broiler) or over a barbecue
for 6-8 minutes, turning to ensure an even color. Meanwhile, make the
mango dip. Process the mango flesh with the chilies, fish sauce, lime
juice, sugar and salt until smooth, then add the coriander.